Dear Nereid and Phobos (seat belt on) can we talk about redshifts?

[turbo]

Yes, Russ, I'm strapped in for the ride, but I think it's a worthy prospect. I truly would like to discuss the problems that arise when strict interpretations of redshift=recessional velocity=distance are applied to every visible extra-galactic body. We need to get beyond this. I don't think all of Arp and Burbidge's ideas are perfectly developed, but their observations are valid and worthy of discussion.

 

[Nereid]

I just posted a response to the moving of the other thread to TD; it's rushed and I'm not at all happy with what I wrote.

Phobos, chroot: is there some way we can cut&paste turbo-1's two excellent posts, and Phobos' reply, into this thread? It's a great shame the other thread was, in fact, at least three different ones

 

[meteor]

This is the last paper of Arp in Arxiv. It can be interesting for the discussion
http://arxiv.org/abs/astro-ph/0401103
New optical spectra and general discussion on the nature of ULX's
Authors: H. Arp, C. M. Gutierrez, M. Lopez-Corredoira
Comments: submitted to A&A, 8 pages, 5 ps/eps figures

"We present spectroscopic observations of three Ultra Luminous X-ray sources (ULX's). Two of them are very close to the active galaxy NGC 720 and the other is near NGC 1073. The two around NGC 720 turn out to be quasars at z=0.964 and z= 2.216, the one near NGC 1073 seems to be associated to an HII region at the redshift of NGC 1073. We concentrate our analysis on the two quasars and analyze them in conjunction with a set of 20 additional X-ray sources close to nearby galaxies which also fit the criteria of ULX's and which also have been identified as quasars of medium to high redshift. This sample shows an unusually large fraction of rare BL Lac type objects. The high redshifts of these ULX's and their close proximity to their low redshift, supposedly parent galaxies is a surprising result in the light of standard models. We describe the main properties of each of these objects and their parent galaxy, and briefly discuss possible interpretations."




I don't think that Arp is a crackpot, he did a good catalogue of extragalactic objects. But his ideas about intrinsic redshifts seems plain wrong to me.

PS: I've read the article, and at the end of it there's this phrase:
"Another suggested explanation for these association of galaxies and quasars with different redshifts is mesolensing by King objects"

What's mesolensing? What are King objects? I've never heard of that

 

[shrumeo]

are these folks trying to discount Harp's interpretations? they don't say outright, only something about "previously proposed ideas"
http://arxiv.org/abs/astro-ph/0310296

can they use their models to predict the redshift differences between the apparenty associated quasar images?

reading the paper, it seems badly translated and parts of it i can't make sense of
grammatically, and yup, the math is over my head, it being optics and gravity and such.

yes, and what is a KING OBJECT, can't find anything about it

edit:
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=ATROES000041000004000436000001&idtype=cvips&gifs=yes

i guess they are supposed high mass objects in the halos of galaxies??
or are they lots of mass spread out over large areas in the halo?

 

[turbo]

mesolensing

Mesolensing is in between microlensing (point-like mass) and macrolensing (galactic-like mass) and has been proposed as a means by which to indirectly observe CDM. The means proposed is to observe multipli-imaged quasars and to record any phasing anomalies, and from those infer the mass and/or extent of the CDM doing the lensing.

King objects aren't a class or type of object, if I understand correctly, they are objects that conform to a particular model of mass distribution, and they have been invoked in the form of galactic halos to explain away the statistical preference in some studies for quasars to appear in closer (angular) proximity to galaxies than can be accounted for by chance.

 

[big-egg]

Can somebody tell what are the indications that
the two quasars are at nearly equal distance from us?

Are there firm indications?

 

[turbo]

Interacting objects of disparate redshifts.

Seyfert galaxy NGC 7603 z=0.029 is connected to its apparently ejected companion z=0.057 by a luminous bridge in which are embedded two compact emission line objects of z=0.243 and 0.391. Scroll down to the images for a look, then read the paper.

http://arxiv.org/abs/astro-ph/0203466

Conservative astronomers claim that these compact high redshift objects are at the distances implied by the Hubble redshift model and the filament is coincidentally projected over them. They also claim that the companion 7603B is at the cosmological distance implied by its redshift which raises the question: Why is there a luminous bridge connecting the two objects if they are too far apart to interact?

A similar question may be asked of M51 and its companion NGC 5195. The conventional answer is that NGC 5195 interacted with M51 a long time ago and is now much farther away, as implied by its redshift. This explanation falls apart pretty readily when viewing deep exposures of the pair, as there is significant tidal action evident, and large masses of material have been displaced from the arms of M51, apparently by the ejection of NGC 5195. Notice the bright blue regions on the inner arm and how they extend out along the path of ejection toward NGC 5195. The path of ejection is apparently in the plane of M51 and not oriented away from us.

http://housefly.astro.princeton.edu/~rhl/PrettyPictures/M51-4x4.jpg

There are many, many more examples of small high-redshift companions interacting with lower-redshift parent galaxies. The conventionalists can explain away individual examples by positing that the the smaller companions are now farther away than the parent galaxies because they have been moving away from us since the (long-ago) interactions. There is a fatal flaw in this thinking: it places us (the observer) in the most special place in the whole universe because the paths taken by these companions all point away from us as implied by their excess redshifts relative to the host galaxies. This simply cannot be true.

It should be evident from these two cases alone that equating redshift with cosmological distance is problematic at best. There are many more examples of interacting high-redshift objects with larger lower-redshift galaxies, though, and I will keep trotting them out, if necessary. If anybody would like to show us a small physically-interacting companion with a LOWER redshift than its host galaxy, please post a link.

What are the benefits of exploring alternative causes of redshifts? The most obvious benefits would be the "normalization" of quasars. If quasars are at the extreme distances implied by their redshifts, they must each possesses the luminosity of thousands of galaxies. Furthermore, since many of them exhibit very short-term brightness variations, they cannot be very large - perhaps smaller in extent than our solar system. Since quasars are presumed to be very early, old objects, they must be tremendously organized and concentrated clumps of matter formed very shortly after the Big Bang. What kind of object can be smaller than our solar system and exhibit the energy output of a thousand galaxies, each containing billions of stars? And how could they have organized themselves so readily in such a short period of time? These are very real problems. Big Bang cosmologists have painted themselves into a corner with these outlandish quasar properties, and the corner gets tighter with every "farthest quasar yet" announcement.

To preserve the Big Bang, many are willing to embrace the existence of such implausible monsters. I find the existence of inherent redshifts far easier to stomach. The real question at this point is: what can cause inherent redshift in quasars and other objects? I lean toward a purely gravitational causation because of its simplicity, but the astronomical community needs to address the issue honestly and with some dedication before we can make progress in this regard.

 

[shrumeo]

hey, somebody school me on some astronomy!

in this pic http://housefly.astro.princeton.edu/~rhl/PrettyPictures/M51-4x4.jpg

these are two galaxies right?
they must be relatively close to each other to be in the same frame and similar in size? am i wrong? is that not how it works? if they were the same distance apart as say the milky way and andromeda, could someone in another galaxy snap that shot of us from the right angle? Would the milky way and andromeda have similar or different redshifts from that perspective?

Just seeing if anyone has answers to these questions.

 

[shrumeo]

i've seen this paper before http://arxiv.org/PS_cache/astro-ph/pdf/0203/0203466.pdf

when one really looks skeptically at the image, you can explain it away as coincidence that the larger object has a little tail, and the 2nd larger object just happens to be behind it, and the two smaller objects are far behind the tail

I would need to see more examples like this to call it anything other than a coincidence.

 

[turbo]

hey, somebody school me on some astronomy!

in this pic http://housefly.astro.princeton.edu/~rhl/PrettyPictures/M51-4x4.jpg

these are two galaxies right?
they must be relatively close to each other to be in the same frame and similar in size? am i wrong? is that not how it works? if they were the same distance apart as say the milky way and andromeda, could someone in another galaxy snap that shot of us from the right angle? Would the milky way and andromeda have similar or different redshifts from that perspective?
Just seeing if anyone has answers to these questions.

Yes, if someone were in the right place, they could photograph our galaxy overlapped by an arm of Andromeda. It would be obvious by the lack of distortion or disturbance of Andromeda's spiral arm, however, that the galaxies are a line-of-sight pair and not interacting.

If you take the name of the jpg out of the URL and paste the remaining URL into your browser, you will find yourself of the Princeton Pretty Pictures page. There you will fine a MUCH-higher resolution version of the same image. Download that and look at it closely. Notice how distorted and pointed the spiral arm of M51 is close to its companion and notice all the filamentous structure around the companion. These are compelling signs of current interaction.

 

[Nereid]

Just quickly again, and to be sure that we all have the same field of discussion.

Question to turbo-1: the only data we need consider are apparent interactions between high and low redshift objects, which are either galaxies or quasars, right? If not, what else is in the mix, wrt the cosmological redshift-distance relationship?

Assuming it's just apparent interactions between high and low redshift objects, here are a few preliminary remarks:
- we will have to use statistics to examine the incidence of apparent interactions between high and low redshift objects. Why? Such apparent interactions are certainly rare among Local Group galaxies, and among Virgo cluster ones (the distances to such can be established pretty reliably, and redshifts of these - and almost all but the faintest galaxies and quasars - accurately determined). Being rare, the Arp hypothesis can be properly tested only statistically against the null hypothesis (presumably, that they are coincidences)
- the determination of the distance of an object, independently of its redshift, is important. We should therefore take a good look at what methods are used to make distance estimates, their domains of applicability, the accuracy and consistency of such estimates, etc (this is a fascinating topic of its own)
- galaxies interact gravitationally (duh!), and plenty of them collide. This means that there will be ‘local’ motion of galaxies – the Milky Way toward M31 (Andromeda galaxy), LMC and SMC in orbit around the Milky Way, and so on. Within a cluster, these local motions can be analysed to produce estimates of the total mass within the cluster (assumptions apply); the redshifts which arise from local motion are not part of the expansion of the universe
- quasars and AGNs: we should look at the current models, and discuss the evidence that quasars ‘live’ in galaxies (or, that quasars are ‘merely’ the active nuclei of some galaxies)

Re NGC 7603 and López-Corredoira and Gutiérrez’ paper: IIRC, this was discussed earlier here in GA&C in PF; I think I posted links to HST observations of this object (so we could see for ourselves what the high-z emission line objects look like, at greater spatial resolution), and commented that their calculations of probability (that such an alignment in a filament would arise by chance) were flawed, principally because they didn’t take account of the fact that fainter objects are distributed in a non-uniform way across the sky. In a sense, what López-Corredoira and Gutiérrez did is analogous to assuming that high latitude interstellar absorption is uniform (we know – thanks to IRAS – that it’s not; there are intricate ‘interstellar cirrus’ clouds!)

 

[Phobos]

Phobos, chroot: is there some way we can cut&paste turbo-1's two excellent posts, and Phobos' reply, into this thread? It's a great shame the other thread was, in fact, at least three different ones

Now that the thread is in the TD forum, I can't mess with it. Chroot?
For now, here's a link to the TD parent of this spinoff thread...
https://www.physicsforums.com/showthread.php?t=29666&page=1&pp=15

 

[Nereid]

If anybody would like to show us a small physically-interacting companion with a LOWER redshift than its host galaxy, please post a link.

I believe that the http://www.seds.org/messier/more/local.html provides strong evidence that it's physically interacting with the Milky Way, and it most certainly is small!

But perhaps this isn't what you meant; would you care to re-state?

 

[turbo]

Ground-rules

Just quickly again, and to be sure that we all have the same field of discussion.

Question to turbo-1: the only data we need consider are apparent interactions between high and low redshift objects, which are either galaxies or quasars, right? If not, what else is in the mix, wrt the cosmological redshift-distance relationship?

Yes, I think it's appropriate and sufficient to look at apparently-interacting bodies of discordant redshifts. By discordant, I mean a difference significant enough to rule out physical interaction if the objects are presumed to be at the cosmological distances suggested by their redshifts. If even one pair of objects has sufficiently-discordant redshifts to rule out the possibility of interaction and they are observably connected and/or interacting, then the policy of placing every object at the distance dictated by its redshift is negated. I know that there is a cadre of prominent astronomers that have been working at this for many years, but there have been a lot of factors muddying the waters, too, including egos and old grievances. I hope that there can be a rational discourse on the subject on PF, and if there are serious problems with arguments on either side, they can be talked over without anybody fearing the loss of their funding or position. I am an amateur observer/astrophotographer and have no real stake in these cosmology issues.

Nereid - your suggestion of using the SMC and the Milky Way is interesting, since the redshift component is due to the proper motion of the SMC toward us. That's not what I had in mind, though - you knew that, but I don't mind being tweaked for imprecise statements. The core problem - there are objects like M51 and its companion that are evidently interacting, but have disparate redshifts. If similar pairs are observed, the smaller companion should be traveling toward us (as opposed to away from us) as suggested by its redshift, about 50% of the time. My request was for examples of apparently-interacting pairs where the smaller component has a lower redshift than the host galaxy. If the interactions are real, and the smaller components have predominantly higher redshifts than the host, we must conclude on the basis of cosmological redshift that ejection phenomena and collision events always throw the smaller object away from us - an impossibility.

 

[shrumeo]

I asked this question on one of the other threads somehow related to this one. But this topic got spread all over.

It's a dummy, layman question about the optics of the whole apparently-connected-disparate-redshift objects discussion.

It seemed there were a few papers cited (above, in this thread?) that claimed to explain the "Arp objects" as a result of gravitational lensing.

If I were an expert in gravitational lensing, would I expect to see distortion within the images of the quasars? I have seen numerous examples of grav. lensing effects and they are all distorted into arcs or streaks. The "Einstein cross" looks like normal intact objects, but how much "refining" do astronomers do to their data when constructing an image like that? Or are the normal visible images not so "retouched." I'm sure these are stupid questions.

I guess what I'm asking is are these papers claiming to be able to predict the nature of images collected by Arp? Or, are they merely offering an alternative explanation for these observations?

 

[turbo]

Lensing has been cited, yes, but the more insidious claims have been the claims of statistical bias. It goes like this: Arp thinks quasars might be ejected from Seyferts and other active galaxies so he searches around them for quasars, and when he finds them, the finds are automatically statistically invalid because he had the temerity to look there. The conventional view claims that he found an apparent excess of quasars around AGN's simply because he looked near them, and if he would just search all the rest of the sky (he might be too old to pull this one off... ) his observations would fall apart. One problem with this is that the conventionalists explain away every example of discordant redshifts with the claim that Arp's methodology is flawed. Not just Arp, by the way, but the handful of observational astronomers who are still questioning the inflexibility of the redshift=distance rule.

Then when Arp observes that the *highest-redshift* quasars in apparent ejection chains are nearest the active galaxy and the quasars with higher angular separation tend to have less excess redshift, this is also explained away as a statistical problem due to his careless selection of quasar candidates. The problem with the argument of the nay-sayers is that if a significant percentage (and not EVERY SINGLE ONE) of the quasar chains *are* oriented with the higher-redshift quasars nearer the host galaxy, a really significant cosmological problem presents itself. The quasars have somehow conspired to arrange themselves so that if plotted by redshift=cosmological distance, they have lined themselves up in inverted cosmological V's pointing directly away from us. It places us, the observers, in the most special place in the universe, which is impossible.

I don't want to wander too far afield, here, though. If we can discuss the evidently interacting pairs of objects in light of their redshifts, it should keep the discussion focussed...well at least maybe it won't turn into a free-for-all.

 

[quartodeciman]

Turb,

I have read that there are photos of galaxies and apparently associated quasars where the red shifts are concordant. What would be the special significance of these? (maybe quasar shot out sideways?)

Should there not be an occasional quasar that is slightly blueshifted? (if the shifts were entirely cosmological then that would never happen)

 

[Nereid]

For those interested (e.g. turbo-1 ), this is the earlier thread with a discussion of NGC 7603 and López-Corredoira and Gutiérrez' paper

 

[shrumeo]

turbo-1, speaking of statistics, how many of these objects have been found so far?

quartodeciman, I don't think they have found enough objects like this to find the one quasar that is being ejected toward us. Also, if the redshift is not attributable to the motion toward or away from us (as Arp claims) then we would also never see a blue shifted quasar "comin' at us".

Also, turbo-1, you say that the redshift seems to be a function of the distance to the galaxy? Can this be explained in terms of gravitational lensing? Again, where is the distortion? (And, of course, lenses have distortions to answer an earlier post, and I'd hope that astronomers correct for them, otherwise this is all a waste of time. After that, where are the distortions normally caused by gravitational lensing?)

 

[Nereid]

Unified model of AGN

http://www.mssl.ucl.ac.uk/www_astro/agn/agn_unified.html has a brief overview of the unified model of active galactic nuclei (AGN), and includes a (very) brief summary of some of the key terms we'll likely encounter - Seyferts (Types 1 and 2), BL Lac objects, AGN, BLR, NLR, accretion disk, jet, ... (be sure to click on the links!).

There are lots of other observations which are now falling into place, wrt this unified model; e.g. 'dark quasars' (X-ray objects that have no optical - or radio - counterpart; X-ray spectrum resembles highly obscured quasar).

Lastly, a nice picture of a molecular torus of an AGN.

 

[meteor]

Gibson tries to explain the redshifts discrepancies in the Stephan's Quintet with his hydro-gravitational theory...
http://arxiv.org/abs/astro-ph/0304107
Interpretation of the Stephan Quintet Galaxy Cluster using Hydro-Gravitational Theory
Authors: Carl H. Gibson (UCSD), Rudolph E. Schild (Harvard)
Comments: 21 pages, 3 figures, for Astronomical Journal

Stephan's Quintet (SQ) is a compact group of galaxies that has been well studied since its discovery in 1877 but is mysterious using cold dark matter hierarchical clustering cosmology (CDMHCC). Anomalous red shifts z = (0.0027,0.019, 0.022, 0.022, 0.022) among galaxies in SQ either; reduce it to a Trio with two highly improbable intruders from CDMHCC, or support the Arp (1973) hypothesis that its red shifts may be intrinsic. An alternative is provided by the Gibson 1996-2000 hydro-gravitational-theory (HGT) where superclusters, clusters and galaxies all originate by universe expansion and gravitational fragmentation in the super-viscous plasma epoch (after which the gas condenses as 10^{24} kg fog-particles in metastable 10^{36} kg dark-matter-clumps). By this fluid mechanical cosmology, the SQ galaxies gently separated recently and remain precisely along a line of sight because of perspective and the small transverse velocities permitted by their sticky, viscous-gravitational, beginnings. Star and gas bridges and young-globular-star-cluster (YGC) trails observed by the HST are triggered as SQ galaxies separate through each other's frozen baryonic-dark-matter halos of dark proto-globular-cluster (PGC) clumps of planetary-mass primordial-fog-particles (PFPs). Discordant red shifts (from CDMHCC) between angularly clustered quasars and bright galaxies are similarly explained by HGT.

 

[Nereid]

In the other thread, I mentioned that whatever Arp et al had found two decades or so ago, they should be able to find 10x, 100x, or more of in the publicly available datasets. I'd love to have enough time to go through each of these, and compare them with what was available to Arp et al all those years ago (but I don't).

Suffice it to say that these data sets are incomparably richer than anything available when Arp first started his professional career. Too, the tools to analyse such vast quantities of data have advanced considerably; for example, the average 'home user' PC of today, priced under US$1,000, is something that professional astronomers would have killed for not too long ago.

So, the 2dF Galaxy Redshift Survey, high quality redshifts of ~250,000 galaxies, by the Aussies. http://www.2dfquasar.org/results.html#example, an ancilliary survey, of ~10,000 quasars (QSOs) - results include the discovery of quasar evolution - pure luminosity evolution (and overcomes one of Burbidge's early criticisms of the identification of QSOs as cosmologically distant, namely, that the redshift-apparent brightness relationship shows no obvious 'distance' component).

http://www.sdss.org/background/index.html (Sloan Digital Sky Survey), whose description is just breath-taking: "[SDSS] will systematically map one-quarter of the entire sky, producing a detailed image of it and determining the positions and absolute brightnesses of more than 100 million celestial objects. It will also measure the distance to a million of the nearest galaxies, giving us a three-dimensional picture of the universe through a volume one hundred times larger than that explored to date. The Sky Survey will also record the distances to 100,000 quasars, ...[/color]". The object selection method differs from that of 2dF - and the sky covered overlaps! - so there are lots of opportunities to do nice statistical analyses of completeness etc.

The http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/07/, and earlier HDF and HDF-S ... the Hubble Space Telescope spent hundreds of hours collecting photons from small patches of sky. What's not so widely known - outside the astronomical community - is that the same patches of sky were also observed from the X-ray to radio regions of the spectrum, with a huge range of telescopes and instruments. So the EM output of objects in each field is known across a wide range of wavelengths. Related is GOODS - Great Observatories Origins Deep Survey, in which Spitzer will stare at HDF-N and Chandra Deep South (and Gemini and ESO telescopes will also make detailed studies).

Just one more for now: http://www.subaru.naoj.org/Pressrelease/2004/06/01/index.html , similar in some ways to GOODS.

 

[Nereid]

OK, last one for today ... how do we determine the distance of an object, independently of its redshift? Or, how can the value of the Hubble constant be nailed down?? (remember, the Hubble constant, or H_o, is the local rate of expansion of the universe. Crudely, it's the slope of the redshift-distance line in a plot of datapoints from galaxies; it's units are peculiar - km/sec per Megaparsec!).

This was perhaps the primary goal of the Hubble Space Telescope. The devotion of so much time to what was then the most expensive astronomical instrument is testament to the importance of this result to modern astronomy (and cosmology); the extra-galactic distance scale has been one of the most difficult results to attain, and uncertainties in the determination certainly played a part in the early credibility of Arp et al's papers.

First, a link to the Hubble Key Project papers. Click on ArXiv preprint to get an electronic copy of a paper.

Next, the final paper, "Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant", by Freedman et al.

There are references in this paper - which I encourage PF members and guests to read, it's not that technical, and is one of the milestone papers of modern astronomy - to the following methods of determining extra-galactic distances:
- Cepheids
- Type Ia supernovae
- Tully-Fisher relation
- surface-brightness fluctations
- Type II supernovae
- fundamental plane
- gravitations lensing
- Sunyaev-Zel'dovich.

Perhaps some other PF members would like to post a quick summary of what these methods are?

So, where does all this leave us wrt Arp et al's claims? (At last, something about the main point of this thread!)

Well, for a start, we can be pretty confident that every object whose distance was determined by any of the eight methods above is as far away (in time and space) as that distance estimate (these objects also do not have discordance redshifts). Ergo, they cannot be among Arp et al's list ... or can they?

Then, we should also have a good handle on the "Hubble flow", local deviations from the distance-redshift relationship. Wha? Best example, the Great Attractor.

 

[turbo]

Apparent interaction in 7603.

OK, let's look at some very basic evidence for interaction here. Please open this paper in a new window and scroll down to the two false color images:

http://arxiv.org/abs/astro-ph/0203466

- The measured redshift of 7603 is 0.029, about the same as that of the filament at 0.030.

- The filament ends in the companion labelled Object 1 at redshift 0.057.

- Since Object 1 is about twice as distant as 7603 (from redshift) it cannot be interacting with 7603 unless the delta redshift is non-cosmological.

- The filament is relatively consistent in brightness and extent the entire distance between 7603 and Object 1. If 7603 and Object 1 are at their cosmological redshifts the filament could not connect them, and if the two objects were even mildly separated, the filament would suffer extinction along its extent toward the more distant object.

Now for the high redshift objects. Let's agree that there is a 100% possibility of finding a very bright high-redshift object in an area the size of the close up (1 square arc-minute = 3600 square arc-seconds). Assuming the luminous filament to be 5 arc-seconds across and 60 arc-seconds long, the filament occupies 1/12 the area of the closeup. There is therefore one chance in twelve that the object can appear projected on any part of the filament. Add a second such object and there is one chance in 144 that both can be touching the filament. What are the chances that both of them will be located in the center of the filament, width-wise? How about 1/60 x 1/60 or 1 chance in 3600? And that's if we believe that there is a 100% probability of finding two bright objects of redshift >0.24 in such a small area.

I know that in an infinite universe, there is a nearly 100% probablility of finding any combination of such objects, but we are not in an infinite "observable" universe. Our observable universe is bounded by cosmological horizons and by the ability of our sensors to detect the things we study.

 

[turbo]

In the other thread, I mentioned that whatever Arp et al had found two decades or so ago, they should be able to find 10x, 100x, or more of in the publicly available datasets. I'd love to have enough time to go through each of these, and compare them with what was available to Arp et al all those years ago (but I don't).

Ideally, you would be correct. Arp had access to lots of very deep exposure plates, though, many of which were taken survey-style with the largest telescopes of the day. Today, although there is a MUCH larger body of data, the data is diffuse in the extreme. Just try to find a deep exposure of Parkes 1327-206 or even the more mundane NGC 5296 and its companions. The images available on-line are grainy with poor contrast, compared to the B/W plates he used in his book "Quasars, Redshifts and Controversies".

Today much telescope time on the big scopes is spent searching very small areas with very specialized detectors, and the survey work seems to be relegated to herds of smaller scopes with far less light-gathering power and resolution. The very sensitive detectors available these days help compensate for the loss of light-gathering ability, but nothing resolves like a BIG well-figured mirror.

Someday, bandwidth will be so cheap that we may be able to persuade the "grand dames" of the astronomical world to digitize their precious survey plates and make them available on-line. How would you like to be able to search Palomar's plates and make comparitive observations over a span of decades of exposures? There would be a LOT more observational astronomy done under that model than under today's system.

 

[Nereid]

AFAIK, all the 2dF and SDSS data (to date) is publicly available, as is the HUDF, HDFs, GOODS data, Subaru/XMM-Newton ... in fact, isn't it a Hubble Space Telescope Institute policy that ALL data must be made available to the public (after some time, so the principal researchers can get papers out)? And we're talking here of FITS files, often several GB in size.

Of course, the AAT and SDSS 'scopes aren't as big as Palomar. However, both went pretty deep, so on balance 5-colour CCDs on an optimised 2.5m telescope (plus spectra) isn't obviously poorer than photographic plates on a 5m one.

Did you take a look at the Subaru/XMM-Newton survey? 1.3^o (~1,000 times the area as the HDFs), 200 hours observation time, with an 8m class telescope on Mauna Kea, using modern CCDs (BRi'z' observations, limiting B magnitude 28.2; PSF? don't know for sure, I guess it's ~<0.4"), and with SCUBA, BLAST, Spitzer and GALEX observations planned or under way (as well as detailed spectra, with Melipal).

If you've not done so, check out the http://www.stecf.org/astrovirtel/ ; when that comes on stream, the only thing missing from your dream scenario will be the digitised versions of older plates!

In my list earlier, I left out 2MASS, whose data is all fully in the public domain.

 

[turbo]

Thank you Nereid!

http://www.naoj.org/Science/SubaruProject/SDS/scijust_qsos.html

There is ongoing work that can help eliminate the quasar-candidate selection bias between radio-active and radio-quiet objects. This research should help clear statistical questions surrounding the optical selection criteria for radio-quiet candidates.

 

[turbo]

Turb,

I have read that there are photos of galaxies and apparently associated quasars where the red shifts are concordant. What would be the special significance of these? (maybe quasar shot out sideways?)

Should there not be an occasional quasar that is slightly blueshifted? (if the shifts were entirely cosmological then that would never happen)

Can you find a reference? It would be interesting to read the paper(s).

 

[Nereid]

Now that the thread is in the TD forum, I can't mess with it. Chroot?
For now, here's a link to the TD parent of this spinoff thread...
https://www.physicsforums.com/showthread.php?t=29666&page=1&pp=15

OK, so here are the previous posts, in chronological order:

An immediate problem I see with the suggested "qualitative" approach (if I understand it correctly) is that it builds the explanatory model first and then finds the data that supports it (ignoring the data against it). In short, a scientist practicing this method would not look for data that can falsify the theory, which is an important part of the scientific method.

As I understand it, Burbidge, Arp, et al, are objecting to just this kind of behavior in regard to the Hubble redshift/distance concept. Not only the fault of not looking for insupportive data, but even worse, the ignoring of existing evidence to the contrary. From a basic web page on the scientific method (http://teacher.nsrl.rochester.edu/p.../AppendixE.html ):

I. The scientific method has four steps

1. Observation and description of a phenomenon or group of phenomena.

2. Formulation of an hypothesis to explain the phenomena. In physics, the hypothesis often takes the form of a causal mechanism or a mathematical relation.

3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations.

4. Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.

If observation (for example the observation of apparently causually connected objects with widely disparate redshifts in the case of Burbidge and Arp) disagrees fundamentally with accepted laws, the Scientific Method demands that the observations be examined, disproved, or proved, THEN back to step 2, when the hypotheses are re-examined, if necessary. Unfortunately, the astronomical community has not comported itself well in this regard, and refuses to examine the apparently disparate redshifts critically. There are a number of very compelling examples of apparently physically-associated items with discordant redshifts, but there is precious little attention given to these quandries. It may be that there are other mechanisms beside cosmological expansion that can cause redshift, and the astronomical establishment does itself a disservice to dismiss examples of discordant redshifts so high-handledly without exploring the alternatives.

It may be that the Big Bang is safe and sound, once apparently non-cosmological redshifts are examined and explained. Alternatively, the Big Bang might be threatened if the Hubble constant is re-examined critically. Either way, if the folks that feel that the Hubble constant is flawed should get a fair hearing.

In a June, 1988 letter to me, Halton Arp wrote "While attending the 'Cosmology in Retrospect' symposium in Bologna a few weeks ago I had occasion to reread some of Hubble's old papers. It surprised even me. Hubble always said - 'if the redshift means velocity.' Even in a paper published after his death in 1953 he said that cxz=velocity is not formally correct."

Halton "Chip" Arp is not a crackpot, or even a fringe observational astronomer. He is one of the 20th century's premier observational astronomers, and he has worked closely with some giants of the field. His survey of "interesting" (in the Chinese sense) galaxies is pivotal. When an astonomer of his magnitude makes some very basic repeatable observations and suggests that we need to re-examine some widely-accepted beliefs, we should pay some attention.

quantum physics [and Godel, for that matter] predict a certain amount of 'unpredictability' in observations. the best fit theory is as good as it gets. scientists are not dogmatic fools... some of them even have children to support. grant money is not free. they are very careful about what they publish because a single mistake could put an end to their credibility and careers.. or force them to write blame-game occult books about their failed theories to make a living.

 

[Nereid]

continued ...

Quantum physics deals with the properties and behavior (or lack thereof...) of fundamental particles. It cannot be used to explain variability in macro-world measurements. Variations in measurements of redshift (observations) are not a factor in any case.

There is no dispute that the high-redshift objects cited by Burbidge and Arp are redshifted. The dispute arises out of the insistence of conventional astronomers that redshift is an absolute measure of recessional velocity and thus of distance. Strict interpretation of redshift=distance places quasars very far away, and requires them to be far more luminous than can be accounted for. To complicate this, jets associated with some quasars exhibit apparent superliminal movement which can only be rationalized by asserting some very coincidental alignments. Also, some quasars exhibit brightness changes over short periods of time, suggesting that they are very compact objects. These problems disappear IF quasars are relatively nearby objects and not the most distant observable bodies.

There may be a reasonable explanation for the excess redshift. For instance, quasars might be tremendously massive and compact, and the light from them is redshifted due to climbing out of a steep gravity well. There may be another explanation, but this particular one is so simple and fundamental that it is probably correct - flying in the face of Einstein, who said "elegance is for tailors". :-)

Unfortunately, the astronomical community has not comported itself well in this regard, and refuses to examine the apparently disparate redshifts critically. There are a number of very compelling examples of apparently physically-associated items with discordant redshifts, but there is precious little attention given to these quandries.

Do you have some examples we can review?

It may be that there are other mechanisms beside cosmological expansion that can cause redshift, and the astronomical establishment does itself a disservice to dismiss examples of discordant redshifts so high-handledly without exploring the alternatives.

Astronomers recognize cosmological, gravitational, and velocity (doppler) sources of redshift.

In a June, 1988 letter to me, Halton Arp wrote "While attending the 'Cosmology in Retrospect' symposium in Bologna a few weeks ago I had occasion to reread some of Hubble's old papers. It surprised even me. Hubble always said - 'if the redshift means velocity.' Even in a paper published after his death in 1953 he said that cxz=velocity is not formally correct."

I have not reviewed Hubble's original papers but even so, a lot of work has been done since that time which is not based on an assumption from his work.

Halton "Chip" Arp is not a crackpot, or even a fringe observational astronomer. He is one of the 20th century's premier observational astronomers, and he has worked closely with some giants of the field.

I think its fair to say that he's outside of the mainstream scientific community. (Not that it automatically discounts his work of course, but peer review is important.)

an astonomer of his magnitude

good pun

 

[Nereid]

continued (2) ...

Do you have some examples we can review?

he is talking about the Arp objects: http://members.aol.com/arpgalaxy/

there are 388 catalogued http://members.aol.com/arpgalaxy/arpord.html

they are all galaxies/quasars that are clearly close enough to touch/interact- but a doppler redshift would indicate that they are very far away from one another-

I think there is probably some weird gravity effects going on here to cause the discrepancy without the need to attack the doppler-from-expansion or the BB- but unfortunatley mainstream cosmologists and even some astronomers ignore this data because it is often used to discredit the Big Bang- so we are all still waiting for a hypothesis from mainstream science- and waiting- and waiting-

Dear Phobos:

Rather than quote, re-quote, etc (kind of messy) I’ll address your quotes one by one.

#1 For some examples, let’s pick just two examples, to keep things manageable:

Here is a link to some information about NGC7603 with two high-redshift knots embedded in the arm connecting the galaxy to its apparently-ejected neighbor. Accidental alignments like this should boggle the mind. If anyone would like to calculate the chances of this alignment, please chime in.

http://quasars.org/ngc7603.htm

Here is a Hubble image of NGC4319 and Markarian 205. Click on the photo and then download the high-resolution version. Open it in Photoshop and manipulate the contrast and brightness settings. The bridge between the two will jump out at you. The Hubble Space Telescope took this picture – there is no sleight-of-hand here. The official version of the image is pretty mundane. Even minor enhancement brings out the bridge, though.

http://hubblesite.org/newscenter/ne...leases/2002/23/

#2 Yes, of course astronomers acknowledge that there are various means by which light can be redshifted. The problem is that the astronomical community has determined that the observed high redshifts of quasars are primarily (read “entirely”) cosmological. If there is even ONE convincing example of a physical relationship between a high-redshift object and a low-redshift object, this rule-of-thumb is automatically void and needs to be re-validated.

#3 I have no access to Hubble’s original papers either. Halton Arp has been privileged to work with some of the finest observational astronomers, however; well before their work was entombed by the assumptions of others. His first position after attaining his doctorate was as Edwin Hubble’s assistant, and I expect that he has a deeper appreciation for Hubble’s thought-processes than most contemporary astronomers. The quote is from a fairly long letter Dr. Arp wrote to me in response to another letter I had written to an astronomy magazine in regard to the apparent bridge between Q2203 +292 and a nearby spiral in a recently published photo. He wanted to convey to me that even Edwin Hubble was uncomfortable with the current fad of using redshifts to establish the distance to every observable object. There is an old saying - “to a man with a hammer in his hand, every problem looks like a nail”. It might now be appropriate to ask if the Hubble Constant has been plastered onto quasars and other high-redshift objects even before the natures of such “quasi-stellar” objects have been adequately explored.

#4 Being outside the mainstream does not invalidate Arp’s work. Copernicus and Galileo were outside the mainstream. Einstein was outside the mainstream. People who make paradigm-altering observations are always outside the mainstream until their observations are accepted. That does not make them wrong, nor should it lay them open to ridicule. I wonder how Galileo would have survived under “peer review” if he had not already used his telescopes to demonstrate to other inquisitive individuals that he was onto something. He probably would have died very early in the inquiry, like the other heretics.

#5 Not a pun (although I love them). Halton Arp is a real gentleman. 50 years from now, the people who have done their very best to bury him in these past few decades will be discredited and many will be reviled for their efforts to discredit him. He is a decent man, and he comports himself with dignity.

 

[Nereid]

Last one (can't resist) ...

ditto...hang on, Turbo1

Oy - fasten your seat-belt, turbo1. You don't know what you just got yourself into...

I must say that I really have no idea what Russ could have meant! :surprise: :shy:

 

[Chronos]

Now for the high redshift objects. Let's agree that there is a 100% possibility of finding a very bright high-redshift object in an area the size of the close up (1 square arc-minute = 3600 square arc-seconds). Assuming the luminous filament to be 5 arc-seconds across and 60 arc-seconds long, the filament occupies 1/12 the area of the closeup. There is therefore one chance in twelve that the object can appear projected on any part of the filament. Add a second such object and there is one chance in 144 that both can be touching the filament. What are the chances that both of them will be located in the center of the filament, width-wise? How about 1/60 x 1/60 or 1 chance in 3600? And that's if we believe that there is a 100% probability of finding two bright objects of redshift >0.24 in such a small area.

I know that in an infinite universe, there is a nearly 100% probablility of finding any combination of such objects, but we are not in an infinite "observable" universe. Our observable universe is bounded by cosmological horizons and by the ability of our sensors to detect the things we study.

I think it is reasonable to predict, given the number of galaxies we can observe, that it is highly improbable such coincidences would not be found. The article Nereid referred to regarding HST findings related to the Hubble constant is much more convincing than Arp's portrait gallery of freaks of nature.

I also think Arp, while well intended, is statistically challenged and has a history of using dubious math to arrive at equally dubious conclusions: which is why he does not have much mainstream support. A good example is the Newman-Terzian paper http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995ApJ...441..505N&db_key=AST&high=3325b47acc06425

The book of nature lies continuously open before our eyes (I speak of the Universe) but it can't be understood without first learning to understand the language and characters in which it is written. It is written in mathematical language, and its characters are geometrical figures. - Galileo Galilei

 

[Nereid]

This recent study of a very massive, mid-distance cluster (z~=0.5) combines observations from Chandra, Keck, Subaru, and Gemini-N. It is part of a set of programs aimed at discovering the evolution of LSS (large scale structure), in particular how galaxy clusters came to have the size and structure that we see today. The role of 'filaments' is important in this.

Interestingly, the astronomers found indications that "significant dynamical activity at scales greater than 5 Mpc from the cluster, well beyond the virial radius. The observations imply an in-fall of matter along this preferred axis direction. The funneling will persist for roughly the next 4 Gyr, assuming an in-fall speed of ~1000 km/s.[/color]"

 

[Nereid]

GOODS result

Hubble, Galaxies Across Time and Space is an IMAX film based on the GOODS survey.

As there are ~30,000 galaxy images in GOODS, of which ~11,000 have measured redshifts, this might be a good test of the Arp hypothesis - how many 'discordant redshifts' appear in the GOODS data? AFAIK, all results are in the public domain, so anyone can check the selection methods used, for determining what constitutes a 'galaxy', and for interpreting spectra in terms of redshift.

In some ways it's a pity this is already 'finished'; otherwise we could ask Arp (or supporters) what they would expect to find in such a survey, and compare their predictions with the observations.

 

[Nereid]

How big are the public GOODS* data files? Seat belts on please (just the HST BViz observations) ... " The files for each section, both the science and the weight map images, are ~268.4 MB in size each (8192 x 8192 pixels, each with a 32 depth), and there are images in each of the four GOODS passbands. Thus, the CDF-S data set requires 2x268.4x18x4 = 38.655 GB, the HDF-N requires 2x268.4x17x4 = 36.507 GB. The full data set requires 38.655 + 36.507 = 75.162 GB.[/color]"

*"GOODS will survey approximately 300 square arcmin divided into two fields: the Hubble Deep Field North and the Chandra Deep Field South. These are among the most data-rich portions of the sky, and are the sites of the deepest observations from Hubble, Chandra, ESA's XMM-Newton, and from many ground-based facilities. Dividing our survey area provides insurance against cosmic variance due to galaxy clustering, and guarantees that astronomers in both hemispheres can carry out related observations.[/color]" ... and Spitzer too.

 

[big-egg]

Questions?

Are the disparate red shifts associated only with quasars and galaxies?

Are there coupling galaxies with disparate red shifts?

Are there supernovas in the proximity of the quasars?

What about the quantum red shifts? They will also create a hard problem to the BBT.

Are there statistical steadies on disparate red shifts?

Thank you for your time to consider these thought provoking questions.

 

[turbo]

Thank you Chronos

I also think Arp, while well intended, is statistically challenged and has a history of using dubious math to arrive at equally dubious conclusions: which is why he does not have much mainstream support. A good example is the Newman-Terzian paper http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995ApJ...441..505N&db_key=AST&high=3325b47acc06425

I am very surprised that you cited that statistically flawed paper, but I am very happy that you did so. The authors misstated Arp's premise and then applied statistics in a very creative way to downplay the improbability of something truly implausible.

Let's say you have a large galaxy and eleven associated smaller galaxies, clusters, whatever. If the smaller objects are physically associated with (and effected by) the more massive object, we would reasonably expect about half the smaller objects moving around that massive galaxy would be moving toward us relative to the host, and would therefore be blueshifted in relation to the host. If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

In the paper cited above, the authors de-coupled the massive host galaxy from any effects on the associated small objects, and then restated the problem as a simple matter of ordination, saying in effect "there is one in twelve chances for the host galaxy to have the smallest redshift so that's a 1/12 chance for the observation that all the smaller objects will be redshifted relative to the large massive galaxy." That has to be one of the most cynical applications of "statistics" I have seen.

The problem that Arp was illustrating is that lower-mass companions of large galaxies are preferentially redshifted with respect to their hosts (like M51 and NGC 5195). It is easy to statistically refute the significance of this trend with one or two objects, but when smaller objects are overwhelmingly found to be redshifted relative to their host galaxies, there can be only two explanations - either we are at most privileged position in the whole universe, where all smaller objects are preferentially running away from us heedless of the gravitational effects of their host galaxies OR these smaller objects have an additional intrinsic redshift that we don't yet understand. I prefer the latter.

 

[meteor]

"A catalogue of southern peculiar galaxies and associations" (Arp, 1987)
http://nedwww.ipac.caltech.edu/level5/SPGA_Atlas/frames.html

This catalogue includes galaxies that are apparently connected. Can be an useful source of information

Also, in post 119 of this thread
https://www.physicsforums.com/showthread.php?t=3593&page=3&pp=40
I give my explanation of the fact that two objects with different redshift seems to be connected

 

[Chronos]

How can you not give an 8% chance that anyone of 12 objects in a group is the least red shifted among the group? The main point of the Newman-Terzian paper was point out the flawed initial assumption Arp used. Intrinsic red shift is a very unsatisfactory explanation. Why would less massive bodies have more intrinsic red shift than the most massive body in a group? The preponderance of evidence supports the conclusion that z=distance. Arp's 388 potential 'exceptions' should not be given more credence than the overwhelming number of confirmations in support of expansion and the BB model. Exceptions, however, are interesting, and point the way to more refined explanations. That only means the current model is incomplete, not fundamentally wrong. Give credit where credit is due. We already know the current model has problems. Quantum physics and GR just don't mix without a quantum theory of gravity. I don't like the idea of appealing to higher orders of reality to explain the problem. Adding strings and branes, imo, only creates more difficulties than they resolve... 'mommy, where did strings come from?'. I think it is a mistake to stray from the observable universe into the unobservable to find answers. It flys into the face of science as I know it.

 

[turbo]

How can you not give an 8% chance that anyone of 12 objects in a group is the least red shifted among the group? The main point of the Newman-Terzian paper was point out the flawed initial assumption Arp used.

The problem with the "statistical treatment" of the example is that the authors of the paper stripped out causality with regard to the gravitational influence of the largest body - it was ignored completely. If you were to make some observations relating to the movements of bodies in our solar system, surely you would not use a method that disregards the gravitational influence of the sun! This is exactly what the authors of that paper did.

To restate:

There are eleven relatively small objects in the domain of one very large massive object.

The motions of the small objects orbiting the massive host object have a 50:50 chance of being toward us or away from us relative to the host.

If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

This is very basic statement of probability. If there is 1/x probabilty of an object being in a particular state, the probability of a set of objects with y members all being in that state at one time is 1/(x to the y power). It's hard for me to understand how the Newman-Terzian paper was published with such a very glaring basic statistical error.

Intrinsic red shift is a very unsatisfactory explanation.

The explanation may be unsatisfactory, but that does not invalidate the observations. The scientific method requires that if we cannot disprove the observations, we must come up with a model that explains them, and use the model to make testable predictions that can be used to verify, disprove, or refine the model.

 

[Chronos]

Turbo: Objections noted. Not all apparent redshift anomalies have been satisfactoriy explained using the standard model. Progress is, however, being made. So far as Newman-Terzian is concerned, I am not aware of any published studies refuting their position. I would be interested if you know of any references.

 

[Chronos]

Hubble, Galaxies Across Time and Space is an IMAX film based on the GOODS survey.

As there are ~30,000 galaxy images in GOODS, of which ~11,000 have measured redshifts, this might be a good test of the Arp hypothesis - how many 'discordant redshifts' appear in the GOODS data? AFAIK, all results are in the public domain, so anyone can check the selection methods used, for determining what constitutes a 'galaxy', and for interpreting spectra in terms of redshift.

In some ways it's a pity this is already 'finished'; otherwise we could ask Arp (or supporters) what they would expect to find in such a survey, and compare their predictions with the observations.

You may find this interesting: http://arxiv.org/PS_cache/astro-ph/pdf/0208/0208117.pdf

 

[turbo]

Thanks for posting that paper. Similar to your discomfort with intrinsic redshifts, I have a problem getting comfortable with the concept of quantized redshifts. My gut feeling is that there is a very simple understandable reason for discrepant redshifts, and that once we figure out the mechanics, the cause will be something that causes a smooth continuum of redshift, not a stepwise progression.

 

[Nereid]

To restate:

There are eleven relatively small objects in the domain of one very large massive object.

The motions of the small objects orbiting the massive host object have a 50:50 chance of being toward us or away from us relative to the host.

If the host has one object it around it, there is one chance in two (1/2) that the object would be redshifted with respect to the host. If there are two objects, there is one chance in four (1/4) that both objects would be redshifted relative to the host. To save time, we will extrapolate: if there are eleven objects around the host, there is only one chance in 4096 that all eleven objects will be found to be redshifted relative to the host.

This is very basic statement of probability. If there is 1/x probabilty of an object being in a particular state, the probability of a set of objects with y members all being in that state at one time is 1/(x to the y power). It's hard for me to understand how the Newman-Terzian paper was published with such a very glaring basic statistical error.

I'll get back to this in more detail when I've read more, but just quickly ... the tidal locking of Io, Europa, and Ganymede means that the probabilities of 'N moving towards' vs 'M moving away' is not random, so the probabilities turbo-1 describes would not apply (actually, *could* not apply). There's also measurement error - how many 'small' objects would show essentially zero redshift (wrt something), within the measurement error?

 

[turbo]

Nereid, I'll willingly play the devil's advocate on this one. What if you have a cloud of smaller objects that are essentially captivated and falling directly into the larger object without significant orbital motion? Some objects will be redshifted, a smaller number will be blueshifted (because we will miss a portion of those objects due to obscuration by the host galaxy) and those objects that are dropping into the host galaxy on a plane perpendicular to our line of sight will exhibit the same redshift as the host.

Assuming NO orbital motion (direct infall only), and an obsuration of blueshifted objects of 10%, and non-discrepant redshift due to perpendicular orientation of infall paths of some objects (maybe another 10%), we still have a probability of less than one in 512 that all the small objects that surround the massive host will exhibit an excess redshift relative to the host. This is a far cry from 8% (1/12) cited in Nemnam-Terzian.

I believe that these are very fair, conservative estimates. I don't want to paint you into a corner and try to make you defend the Newman-Terzian paper, but what do you think of their paper?

 

[Chronos]

respect

Thanks for posting that paper. Similar to your discomfort with intrinsic redshifts, I have a problem getting comfortable with the concept of quantized redshifts. My gut feeling is that there is a very simple understandable reason for discrepant redshifts, and that once we figure out the mechanics, the cause will be something that causes a smooth continuum of redshift, not a stepwise progression.

we are in agreement. i respect your objections and agree that current models are lacking. we need better predictive models to sort it out. something is still missing. the universe is a maddening puzzle. it taunts and teases us, but, resists yielding its secrets. i do believe, however, current models are more correct than incorrect. the evidence appears, at least to me, to be overwhelming. the piece still missing, imo, is quantum gravity.

are there observations that contradict expansion as the 'big picture' of the universe? of course. information theory [shannon and godel] insist this will always be the case. will someone find a paradigm shift to further advance our understanding of how the universe works? i hope so. i object to being trapped within a place as small as our solar system. that is what current theory condemns us to and i am not comfortable with that either. if we can see it, we should be able to explore it.

 

[Nereid]

Mesolensing is in between microlensing (point-like mass) and macrolensing (galactic-like mass) and has been proposed as a means by which to indirectly observe CDM. The means proposed is to observe multipli-imaged quasars and to record any phasing anomalies, and from those infer the mass and/or extent of the CDM doing the lensing.

King objects aren't a class or type of object, if I understand correctly, they are objects that conform to a particular model of mass distribution, and they have been invoked in the form of galactic halos to explain away the statistical preference in some studies for quasars to appear in closer (angular) proximity to galaxies than can be accounted for by chance.

Am working my way slowly through the posts in this thread, and have got up to here.

Several questions, and possible lines of investigation, occur to me:
- examine the Arp hypothesis (-ses?), that AGN galaxies (inc Seyferts) eject quasars (yes, that's an oversimplification); that the preponderance of galaxy/quasar discordant redshifts also involve ULX. I'm not sure yet what to do about his galaxy/galaxy discordant redshift observations.
- take a closer look at gravitational lensing - micro, meso, and 'traditional'
- GOODS, 2dF, and SDSS as tests of Arp's ideas. e.g. if there are ~300 'Arp' objects among the ~23k de Vaucouleur catalogue (RC3), then there should be ~300 among the 30k GOODS galaxies, and ~3k among the ~250k 2dF ones, and ~10k among the ~1m Subaru/XMM-Newton ones (many assumptions behind these statements!); are there?
- both 2dF and SDSS should permit a far more rigorous testing of any quasar/(active) galaxy association than finding interesting objects by eye and taking a deeper look; medium-deep surveys should also provide good tests
- among objects whose distance has been established by means independent of redshift, there will likely be some from Arp's catalogue, and surely some Seyferts (etc). What about associated discordant redshift objects? E.g. an SN in both objects of such a pair? We can look for ourselves, because there's a pretty complete list of all SN available on the internet.

Finally, some clarifications on King objects, meso-lensing, CDM cosmology, etc.

One of the challenges for the concordance model ('\Lambda CDM') is that it predicts far more 'small(ish) galaxies' than are actually observed, IIRC between 1 and 2 OOM too many. Now the model doesn't say what sort of things these objects should be, just (approx) what their mass function should be (how many of mass M₁, how many of mass M₂, etc), and (approx) the distribution of mass within them (hence 'King objects'; OK some oversimplification here too). Most importantly, it doesn't distiguish between baryonic matter and dark matter! Enter theories of galaxy evolution, and where it starts to get messy; enter observations, and where it starts to get interesting! Even within the Local Group - the ~20 (30?) galaxies dominated by the Milky Way and M31 - we keep finding more and more things, such as dwarf galaxies like Andromeda 9, dwarf galaxies being shredded by the MW, and inter-galactic clouds of gas. But the critical thing is the DM, which, because it's dark, can't be 'seen' in X-rays, the optical, radio, etc. However, DM objects can be detected through gravitational lensing; the question is, what sort of gravitational lens signature would a DM object leave on the light (radio, X-rays, etc) from a distant quasar? Or, within an Arp hypothesis, what should the results of observations designed to find 'meso-lensing by King objects' be?

 

[turbo]

I wish I had more time... Suggestions, anyone?

There is such a ton of research material available...

Nereid, your suggestions re: SN in Arp objects led me to this great SN list

http://web.pd.astro.it/supern/snear.txt

and I started comparing it to the Arp catalog, which is a pain in the butt. Differences in nomenclature make it very likely that I would miss Arp objects in the SN catalog.

http://members.aol.com/arpgalaxy/arplist.html

I decided to cut to the chase and Googled supernova and Arp and found this article about multiple SN in Arp 299:

http://www.space.com/scienceastronomy/aas202_supernova_030527.html

Which led me to explore Arp 299 in more detail. There is wealth of material in NED, of course, and there is a nice Arp 299 page here:

http://www.cv.nrao.edu/~jhibbard/a299/a299.html

It seems that Arp 299 might be a little "too" complex for the SN data to be really useful, as evidenced by this really busy paper:

http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v532n2/50399/50399.text.html

I will try to locate a more "normal" Arp pair with SN data available. Can anyone suggest a more productive approach to locating SN data in apparently-interacting objects with discordant redshifts?

 

[Nereid]

The list of SN that you found seems similar to the 'official' one, associated with the IAU circulars (CBAT - Central Bureau of Astronomical Telegrams - is currently administered by the Smithsonian Astrophysical Observatory?); http://cfa-www.harvard.edu/iau/lists/RecentSupernovae.html is their list of SN since the start of 2003 (there's also a link to all SN).

You may find the best way to find a match is to put the list into a database or spreadsheet, sort by RA (or dec), filter by close matches to Arp objects (I assume you have a list of their RAs and decs), and examine each such in detail.

Be aware that even the IAU list has errors in it! They seem to be mostly typos (e.g. transposed digits).